Medical Nutrition Therapy
Medical nutrition therapy (MNT) refers to the assessment of the nutritional status of patients with an illness, diet-related condition, or injury, in order to benefit the patient's own health and reduce health-care costs. MNT includes setting goals for the patient's treatment and developing a specialized nutrition prescription that includes patient education and self-management training. MNT, which is also called therapeutic nutrition, has become an increasingly important component of integrated health-care systems.
The purpose of MNT is to identify patients at risk for major nutrition-related health problems and recommend dietary adjustments leading to better health outcomes and improved quality of life. Eight of the 10 leading causes of death in the American population—including coronary heart disease, stroke, diabetes mellitus, and some cancers—are
MNT is also used to treat such disorders as anorexia and bulimia nervosa, cystic fibrosis, irritable bowel syndrome, hyperlipidemia, difficulty with lactose digestion, gastric ulcers, sprue (a malabsorption syndrome), and (in children) failure to thrive. Adequate nutrition is essential to reduce morbidity and mortality from these and other acute or chronic conditions. MNT helps to contain health-care costs while benefiting patients directly by offering alternatives to more expensive drug treatments and minimizing the need for surgery or lengthy hospital stays.
Medical nutritional therapy is used in a variety of treatment settings, including home care and outpatient care as well as acute or long-term care facilities. In most of these settings, medical nutrition therapy includes a comprehensive review of the patient's medical history and a dietary assessment with laboratory values and anthropometric measurements.
A key part of MNT includes an assessment of the patient's current and past diet history. A dietary assessment is often conducted to determine the macronutrient (energy or caloric, protein, and fat) content and the micronutrient (vitamin and mineral) content of the patient's food intake. Some of the most common dietary assessment tools include food records, dietary recalls, food frequency questionnaires, diet histories, and several other methods of data collection, including biochemical indices. A scientific assessment of nutritional status may be compiled from the information collected from clinical evaluations, biochemical tests, and dietary information. The clinical evaluation includes measurements of the patient's height, weight, and percentage of body fat (determined by skinfolds or hydrostatic weighing). In addition, a clinical evaluation may also include observation for signs of nutrient deficiencies in the mouth, skin, eyes, and nails. The information collected from a clinical evaluation is added to the results of the dietary assessment and biochemical tests to provide a comprehensive picture of the patient's current nutritional status and relative risk factors for diet-related illnesses. MNT can then be designed to treat the patient's specific illness or diet-related condition.
In addition to the patient's overall medical history and specific evaluation of any diet-related illnesses or conditions, an intitial evaluation may include an assessment of his or her:
- psychosocial data, including food-related attitudes and behaviors
- sociological data, including cultural practices, housing, cooking facilities, financial resources, and support of family and friends.
- general understanding of nutrition, including the relationship of diet to his or her disease or condition.
- learning style, together with his or her readiness to modify or change behavior.
- current exercise and activity level
- supplemental nutrition for patients who cannot obtain adequate nutrients through food intake alone
- enteral nutrition delivered via tube feeding into the gastrointestinal tract for those unable to eat normally or digest food
- parenteral nutrition delivered via intravenous infusion (IV) for those who cannot absorb nutrients
Patient education is a critical dimension of medical nutrition therapy, in that patient compliance is essential to the success of any preventive or therapeutic nutritional program. Patient education in MNT may include task, guideline, and meal planning exercises. These exercises help to educate patients regarding proper food choices in the treatment or control of their specific illness or condition. Tasks are usually simple and objective responsibilities agreed upon by the dietitian, nutritionist, or doctor and the patient. An example of a task might include the patient's reviewing an itemized grocery receipt with the dietitian to determine if the foods that were purchased were appropriate to the nutrition plan.
A guideline approach provides the patient with nutrition information related to their specific illness, to be applied to their current eating habits. The patient can learn to plan and prepare appropriate meals with the
dietitian's help, and eventually become able to manage their nutritional regimen on their own.
Preventive care at all points along the spectrum of illness—primary (preventing disease), secondary (early diagnosis), and tertiary (preventing or slowing deterioration)—requires active patient participation as well as guidance from the dietitian and physician or nurse. Education, motivation, and counseling contribute to effective patient participation.
There are many nonmedical issues that must be factored into planning appropriate dietary counseling and MNT. Due attention must be given to the patient's usual food choices, food likes and dislikes, cultural values, and the patient's ability to implement the dietary changes. In particular, the attitudes of other family members often influence the patient's compliance. Family members who are embarrassed by a patient's eating disorder, for example, may make her or his eating patterns and weight fluctuations the focus of most of the family's interactions. This focus will tend to reinforce the eating disorder rather than the medical nutrition therapy.
Nutrition therapy will be effective only if the patient is willing to implement the suggested recommmendations. If a patient does not follow the recommended dietary guidance, then they will not receive a health benefit from MNT.
Patients who require continued MNT (parenteral or enteral nutrition) after leaving a hospital should receive frequent follow-up and monitoring by a registered dietitian.
The large-scale results of MNT have been impressive enough in terms of cost-effectiveness to capture the attention of many large companies. A number of registered dietitians are now conducting on-site nutrition classes in corporate workplaces, participating in health and wellness fairs, and working with corporation food services to design more healthful menus, in addition to offering MNT to the firm's employees.
On the individual level, the effectiveness of MNT depends on the commitment of all members of the health-care team—but especially on the patient who has the nutrition-related illness. Prioritized goals are critical when developing the nutrition treatment plan, together with ongoing assessment by the patient and health care team members. Physicians must understand the patient's dietary plan and reinforce the nutrition therapy when interacting with the patient.
The American Dietetic Association maintains as its official position that MNT is an essential and cost-effective part of comprehensive health care services. Medical nutrition therapy is also effective in treating disease and preventing disease complications.
Health care team roles
In general, only registered dietitians (R.D.) have sufficient training and knowledge to accurately assess the nutritional adequacy of a patient's diet. Nutrition support teams, however, include registered dietitians as team members, often as team leaders. Because food and nutrition services span both medical and social contexts, medical nutrition therapy should be an interdisciplinary task in patient care. Physicians should learn the indications for special diets in order to facilitate referrals to dietitians and to reinforce patient compliance. Dietitians are needed to monitor patient populations receiving enteral, parenteral, and specialized oral therapies in conjunction with other health care team members (physicians, nurses/aids, home care workers, etc).
Some insurance plans cover fees for nutritional counseling by physicians and nurse practitioners as well as by registered dietitians directly supervised by physicians or employed by a participating institution. This inclusiveness reflects the growing significance of MNT in health care as well as the importance of coordinating the work of different health professionals in the area of nutrition.
Dietary assessment—An estimation of food and nutrients eaten over a particular time point. Some of the most common dietary assessment methods are food records, dietary recalls, food frequency questionnaires, and diet histories.
Dietary counseling—Nutritional advice provided to an individual patient by a registered dietitian, nutritionist, or doctor for encouraging modification of eating habits.
Dietitian—A health professional with expertise in the field of nutrition and dietetics. Most have a bachelor's degree, followed by a period of clinical training.
Enteral nutrition—Feedings administered through a nose tube (or surgically placed tubes) for patients with eating difficulties.
Parenteral nutrition—Feeding administered most often by an infusion into a vein. It can be used if the gut is not functioning properly or due to other reasons that prevent normal or enteral feeding.
Therapeutic nutrition—Another term for medical nutrition therapy.
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Crystal Heather Kaczkowski, MSc.